Hierarchical mobility management for wireless networks

Abstract

Methods and apparatus for providing a hierarchical mobility management function for routing packets to mobile nodes are provided. The hierarchical mobility management function may be placed anywhere within the network and provide efficient use of IPv6 addresses. A node implementing the hierarchical mobility management function receives packets intended for the mobile node and routes the packets to the mobile node's current address. Load sharing of packets intended for a mobile node may be implemented across several access routers. Additional, bi-casting of packets is provided to allow for seamless handoff of the mobile node as it switches from one access router to another access router.

1. A method for routing packets to a mobile node comprising the steps of:
 providing an address update, including a regional care-of-address associated with the mobile node, to a node communicating with the mobile node;  
 sending packets, from the node communicating with the mobile node, to a node associated with the regional care-of-address;  
 receiving packets at the node associated with the regional care-of-address;  
 determining, at the node associated with the regional care-of-address, a current address of the mobile node;  
 routing the received packets to a node associated with the current address of the mobile node;  
 forwarding packets, from the node associated with the current address, to the mobile node; wherein the packets are sent between the node communicating with the mobile node and the mobile node in accordance with mobile Internet Protocol version 6 (MIPv6) protocol;  
 sending a message, from the mobile node to the node associated with the mobile node's regional care-of-address, requesting that packets be routed to the mobile node's current address and at least another current address of the mobile node;  
 routing a first group of packets, from the node associated with the mobile node's regional care-of-address, to a node associated with the mobile node's current address; and  
 routing a second group of packets, from the node associated with the mobile node's regional care-of-address, to a node associated with the at least another one of the mobile node's current addresses.  
 
   
   
     2. The method of  claim 1 , wherein the node associated with the regional care-of-address implements mobility anchor point functionality. 
   
   
     3. The method of  claim 1 , wherein the node associated with the current address is an access router. 
   
   
     4. The method of  claim 1 , further comprising the step of: receiving a message, from the node associated with the mobile node's current address, by the mobile node, wherein the message indicates the availability of nodes which can be used as regional care-of-addresses for the mobile node. 
   
   
     5. The method of  claim 4 , wherein the nodes which can be used as regional care-of-addresses for the mobile node have mobility anchor point functionallty and wherein the message is a router advertisement containing a mobility anchor point option. 
   
   
     6. The method of  claim 4 , further comprising the step of: receiving the message by the node associated with the mobile node's current address, wherein the message is received by the node associated with the mobile node's current address via a hierarchy of routers. 
   
   
     7. The method of  claim 4 , further comprising the step of: selecting, by the mobile node, a new regional care-of-address based upon information contained in the message. 
   
   
     8. The method of  claim 7 , wherein the new regional care-of-address is selected based upon one of a distance of a node associated with the new regional care-of-address and the mobile node and a preference for the node associated with the new regional care-of-address. 
   
   
     9. The method of  claim 8 , wherein the preference for the node associated with the new regional care-of-address is based upon one of network loading, network failures and local network policies. 
   
   
     10. The method of  claim 1 , wherein the packets are sent from the node communicating with the mobile node to the mobile node without being routed by a home agent associated with the mobile node. 
   
   
     11. The method of  claim 1 , further comprising the steps of:
 sending an update message from the mobile node to the node associated with the mobile node's regional care-of-address, wherein the update message includes an address associated with a node which the mobile node will be using as its new regional care-of-address;  
 receiving packets by the node associated with the mobile node's regional care-of-address; and  
 forwarding the received packets to the node associated with the mobile node's current address and to the node associated with the mobile node's new regional care-of-address.  
 
   
   
     12. The method of  claim 11 , wherein the update message is a binding update and wherein the binding update includes an indication that the mobile node is registering with the node associated with the mobile node's new regional care-of-address, that the mobile node requires bi-casting of packets. 
   
   
     13. The method of  claim 1 , further comprising the step of: determining, by the node associated with the mobile node's regional care-of-address, a load on the node associated with the mobile node's current address and a load on the node associated with the at least another one of the mobile node's current addresses, wherein packets are selected for the first group or the second group based on the determined loads. 
   
   
     14. The method of  claim 1 , wherein the message is a binding update. 
   
   
     15. A network comprising:
 a mobile node;  
 a node communicating with the mobile node, wherein the mobile node provides an address update, including a regional care-of-address associated with the mobile node, to the node communicating with the mobile node;  
 a node associated with the regional care-of-address, wherein the node communicating with the mobile node sends packets to the node associated with the regional care-of-address;  
 a node associated with a current address of the mobile node, wherein the node associated with the current address of the mobile node receives packets from the node associated with the regional care-of-address of the mobile node and sends the received packets to the mobile node;  
 means for sending a message to the node associated with the mobile node's regional care-of-address requesting that packets be routed to the mobile node's current address and at least another current address of the mobile node;  
 means for routing a first group of packets, from the node associated with the mobile node's regional care-of-address, to a node associated with the mobile node's current address; and  
 means for routing a second group of packets, from the node associated with the mobile node's regional care-of-address, to a node associated with the at least another one of the mobile node's current addresses;  
 wherein the network operates in accordance with mobile Internet Protocol version 6 (MIPv6) protocol.  
 
   
   
     16. The network of  claim 15 , wherein the node associated with the regional care-of-address implements mobility anchor point functionality. 
   
   
     17. The network of  claim 15 , wherein the node associated with the current address is an access router. 
   
   
     18. The network of  claim 15 , further comprising:
 means for receiving a message, from the node associated with the mobile node's current address, by the mobile node,  
 wherein the message indicates the availability of nodes which can be used as regional care-of-addresses for the mobile node.  
 
   
   
     19. The network of  claim 18 , wherein the nodes which can be used as regional care-of-addresses for the mobile node have mobility anchor point functionality and wherein the message is a router advertisement containing a mobility anchor point option. 
   
   
     20. The network of  claim 18 , further comprising: means for receiving the message by the node associated with the mobile node's current address, wherein the message is received by the node associated with the mobile node's current address via a hierarchy of routers. 
   
   
     21. The network of  claim 18 , further comprising: means for selecting, by the mobile node, a new regional care-of-address based upon information contained in the message. 
   
   
     22. The network of  claim 21 , wherein the new regional care-of-address is selected based upon one of a distance of a node associated with the new regional care-of-address and the mobile node and a preference for the node associated with the new regional care-of-address. 
   
   
     23. The network of  claim 22 , wherein the preference for the node associated with the new regional care-of-address is based upon one of network loading, network failures and local network policies. 
   
   
     24. The network of  claim 15 , wherein the packets are sent from the node communicating with the mobile node to the mobile node without being routed by a home agent associated with the mobile node. 
   
   
     25. The network of  claim 15 , further comprising:
 means for sending an update message from the mobile node to the node associated with the mobile node's regional care-of-address, wherein the update message includes an address associated with a node which the mobile node will be using as its new regional care-of-address;  
 means for receiving packets by the node associated with the mobile node's regional care-of-address; and  
 means for forwarding the received packets to the node associated with the mobile node's current address and to the node associated with the mobile node's new regional care-of-address.  
 
   
   
     26. The network of  claim 25 , wherein the update message is a binding update and wherein the binding update includes an indication that the mobile node is registering with the node associated with the mobile node's new regional care-of-address, that the mobile node requires bi-casting of packets and the length of time for which bi-casting of packets is required. 
   
   
     27. The network of  claim 15 , further comprising: means for determining, by the node associated with the mobile node's regional care-of-address, a load on the node associated with the mobile node's current address and a load on the node associated with the at least another one of the mobile node's current addresses, wherein packets are selected for the first group or the second group based on the determined loads. 
   
   
     28. The network of  claim 15 , wherein the message is a binding update.